Modular plugs are well-known in the communications industry to permit simple electrical connection and disconnection of communication devices. The modular plugs typically have four, six or eight contacts which are engageable with individual wires of a communication cable received in the plug. The contacts are narrow conductive members which are disposed in initial positions in slots in the plug. The contacts are driven along respective axes of motion into engagement with their respective wires in a crimping operation wherein the contacts are caused to pierce the insulation of their respective wires and to electrically engage the conductive wire core.
Crimping tools are known for driving the contacts of a modular plug into engagement with their respective wires. These crimping tools have a die set comprising a pair of cooperating dies which are driven relatively together, one of the dies having a plurality of indenters which engage the contacts to force the contacts into engagement with the communication cable. Such crimping tools generally have a pair of relatively pivotable handle members which are connected so as to provide a mechanical advantage for driving the dies relatively together.
Many of the known crimping tools have the die set arranged so as to receive the modular plug with the communication cable extending substantially parallel to the handle pivot axis and the contacts arranged in an array at slightly different radial distances from the pivot axis. Such an arrangement provides a relatively narrow tool and enables a tool operator to easily see when the modular plug is properly positioned between the die set prior to a crimping operation. In its simplest form, such a tool has the handle members pivotally attached in a pliers-like arrangement with the die set at a remote end thereof. As the handles are pivoted during a crimping operation the indenters move along an arcuate path and, as the indenters drive the contacts along their respective axes of motion the indenters also slide across the tips of the contacts in a direction transverse to the axes of motion. This results in a problem in that the transverse motion of the indenters tends to rotate the modular plug and may result in binding of the modular plug in the tool and/or binding of the contacts in their slots and/or incomplete engagement of the contacts with their respective wires.
Various tool constructions have been developed in order to overcome this problem. These tools typically have a crimping die on a separate movable block which is guided for straight line motion along a path normal to a nest for the plug. See, for example, U.S. Pat. No. 4,429,451 to Angelico; 4,480,374 to Meyer; and 4,862,580 to Wang et al. These tools have pivotable handles which are operable to move a roller or cam-like actuator against the block. In each of these tools the roller or cam-like actuator moves partially across a face of the block during a crimping operation, thereby resulting in friction and wear. Further, these tools are relatively complex and expensive to manufacture. There is a need for a simple hand operable crimping tool which overcomes the problems associated with the prior art crimping tools and ensures a reliable and secure connection of a modular plug with a communication cable.